Documents U.S. Pat. No. 5,888,224, US 20110015742 and US 20110172774 for example show such spine cages.
U.S. Pat. No. 5,888,224 discloses an implant for the intervertebral space which consists of an essentially cuboid body with a device for gripping by a tool.
US 2011/0015742 shows a spine fusion cage comprises a housing, a movable member, a sliding member and a screw. The upper surface of the housing has an opening through which the movable member can move in a vertical direction. The sliding member is provided within the housing and can move in a longitudinal direction of the spine fusion cage. The movable member has an activation surface. In the case that the activation surface is in contact with the sliding member, movement of the sliding member in the longitudinal direction of the spine fusion cage causes the movable member to move up or down. The sliding member is moved by turning the screw such that the movable member can move up or down.
US 2011/0172774 provides an expandable intervertebral implant that is selectively disposed in the intervertebral space and deployed, thereby in-situ distracting, realigning, and/or stabilizing or fusing a portion of the spine of a patient in the treatment of injury, disease, and/or degenerative condition. The expandable intervertebral implant includes a superior member and an inferior member, each of which has a partially or substantially wedge or prismatic shape and a partially or substantially convex or other-shaped surface that is suitable for engaging the substantially concave surfaces of the associated bony superior and inferior intervertebral endplates. Once disposed in the intervertebral space, the expandable intervertebral implant is actuated and deployed, with the superior member and the inferior member moving apart from one another, seating against the associated intervertebral endplates, and distracting, realigning, and/or stabilizing them to a desired degree. The external surface of each of the superior member and the inferior member is provided with a plurality of ridges or other friction structures, providing purchase with the associated intervertebral endplates.